Great America PAC plans to spend much of its bounty on businessman’s behalf before July convention

A pro-Donald Trump super PAC is ratcheting up activity, setting a fundraising goal of at least $15 million as the New York businessman moves toward clinching the Republican presidential nomination.

Great America PAC last week hired a prominent GOP fundraiser who previously worked for a group backing former Republican presidential contender Rand Paul. The group plans to spend much of its bounty on Mr. Trump’s behalf before the...